This study investigated the effects of in ovo administration of equol (Eq) on post-hatch growth and hepatic lipid metabolism in broiler chickens. Fertilized eggs (146 eggs/group) were injected with 0 μg (control, Con), 20 μg (low dose, L) and 100 μg (high dose, H) Eq in the albumen on the 7th day of incubation. Except a trend increase in the weight of total fat (P = 0.09), Eq had no effect on growth or liver weight in broilers at 49 days of age. Males presented higher liver and BWs and lower total fat and relative liver weights than females (P < 0.01). However, there were no significant effects of Eq or Eq–gender interactions on growth performance or tissues weight (P > 0.05). With respect to lipid parameters in the serum, the results showed that female broilers presented higher triacyglycerol (TG) and low-density lipoprotein cholesterol concentrations than males, whereas there was no gender difference in serum total cholesterol (TC) or high-density lipoprotein cholesterol (HDLC) concentration (P > 0.05). Eq administration significantly decreased serum TG and TC but increased HDLC concentrations in serum of broilers at 49 days of age (P < 0.05), whereas there were no interactions between gender and Eq (P > 0.05). To elucidate the mechanism behind the significant changes of serum TG and TC levels, the expression of genes involved in lipid metabolism in the liver was investigated in female chickens using reverse transcription-PCR. Carnitine palmitoyl transferase I (CPTI) messenger RNA (mRNA) was significantly upregulated by 20 and 100 μg Eq (P < 0.05). High-dose Eq significantly decreased fatty acid synthase (FAS) and enhanced cholesterol-7alpha-hydroxylase (CYP7A1) mRNA levels in the liver (P < 0.05). Eq had no significant effects on acetyl-CoA carboxylase, sterol regulatory element binding protein-1c, malic enzyme, low-density lipoprotein receptor or 3-hydroxy-3-methylglutaryl coenzyme A reductase mRNA in the liver (P > 0.05). These results in female broilers suggest that Eq decreased blood TG by upregulating CPTI and downregulating FAS mRNA expression in the liver, and that high serum cholesterol levels stimulated CYP7A1 gene transcription in the liver.

The effect of increasing the interval between recordings from 1 month to 2 months was studied by analysis of milk, fat and protein yield records obtained in alternate monthly herd visits. The data comprised records on over 34 000 daughters of 40 proven and 705 young sires which were analysed by multivariate restricted maximum likelihood.

Heritability estimates of bimonthly test day records were similar to the average of the estimates for the two corresponding monthly test day records, as were genetic and phenotypic correlations between bimonthly test day and lactation records. A quartic regression removed most of the additional variance due to the wide range of days to first test and therefore the variance-covariance structure of bimonthly test day records could be predicted from that of monthly test day records.

The accuracies of prediction of breeding value for 305-day yields of milk, fat and protein using the sum of five bimonthly test day records and the sum of seven 6-weekly tests were estimated to be at least 0·97 and 0·99, respectively, of the accuracy of using 10 monthly test day records.

If milk yield were recorded daily, prediction of lactation fat or protein yield from the product of the sum of daily milk yields and the average fat or protein content would be more accurate than using yield and content records solely from test days.

This experiment was undertaken to evaluate the effect of dietary vitamin A on the performance and immune competence of broilers under heat stress (HS). A total of 180 birds, at 22 days of age, were randomly assigned to be reared either at 24°C (thermoneutral, TN, 24°C, constant) or 24°C to 38°C (heat stress, HS, cycling) until the age of 42 days. Birds were then supplemented with vitamin A at 750, 1500, 15 000 IU/kg. Each of the 2 × 3 factorially arranged treatments were replicated in six cages, each containing five birds. Humoral immunity was assessed by intravenous injection of 7% sheep red blood cells (SRBC) followed by evaluation of serum for antibody titers in primary and secondary responses. Cell-mediated immunity was assessed by using a Sephadax stimulation method to recruit abdominal exudate cells (AEC) to evaluate macrophage phagocytic ability. Body weight (BW) and feed conversion were significantly affected by dietary vitamin A (P < 0.05). HS significantly reduced BW, feed intake and feed conversion (P < 0.05). Numbers of AEC, percentage of macrophages in AEC, phagocytic macrophages, internalized opsonized and unopsonized SRBC were increased by dietary vitamin A (P < 0.05). Both primary and secondary antibody responses were characterized by increasing titers of antibody to SRBC by dietary vitamin A when birds were exposed to HS (P < 0.05). Lymphoid organ weights, antibody responses, incidence of macrophages in AEC and phagocytic ability of macrophages were all significantly reduced under HS. These results indicated that HS severely reduced performance and immunocompetence of broilers, whereas the immune response of broilers improved by dietary vitamin A supplementation under HS.

Various uses of donkeys’ milk have been recently proposed for human consumption on the basis of its nutritional characteristics. Improvements in milk fatty acid profile and animal oxidative status can be induced through dietary supplementation of phenolic compounds. The study aimed to evaluate in donkeys the effects of dietary supplementation with verbascoside (VB) on: (i) the fatty acid profile and vitamins A and E contents of milk during a whole lactation, and (ii) blood biochemical parameters and markers of oxidative status of the animals. At foaling, 12 lactating jennies were subdivided into two groups (n 6): control, without VB supplement; VB, receiving a lipid-encapsulated VB supplement. Gross composition, fatty acid profile and vitamins A and E contents in milk were assessed monthly over the 6 months of lactation. Serum total cholesterol, high-density lipoproteins cholesterol and low-density lipoproteins cholesterol, tryglicerides, non-esterified fatty acid, bilirubin, alanine aminotransferase (ALT), aspartate aminotransferase, reactive oxygen metabolites, thiobarbituric acid reactive substances (TBARs), vitamin A and vitamin E were evaluated at 8 days after foaling (D0) and then at D90, D105 and D120 of lactation. In milk, the VB supplementation decreased the saturated fatty acids (P<0.05) and increased the monounsaturated fatty acids (P<0.05), and vitamins A and E (P<0.01) values. On the serum parameters, the VB supplementation decreased total cholesterol (P<0.01), tryglicerides, bilirubin, ALT and TBARs, and increased (P<0.01) vitamin E. In conclusion, the VB dietary supplementation affects the nutritional quality of donkey’s milk with a benefit on the oxidative status and serum lipidic profile of the animals.

Flavan-3-ols are a class of flavonoids that are widely distributed in fruits and beverages including red wine and apples. Consumption of flavanoid-rich food has been shown to exhibit anti-microbial, anti-oxidative, anti-inflammatory, and immune-modulating effects. To test the nutritional effects of flavanols on mRNA gene-expression of inflammatory and apoptotic marker genes, piglets were given two flavanoids-rich feeding regimens: a low flavanoid standard diet (SD) was compared with diets enriched with 3·5% apple pomace (APD) or 3·5% red-wine pomace (RWPD). The influence on mRNA expression levels was investigated in different immunological active tissues and in the gastro-intestinal tract (GIT). The investigation took place from 1 week prior weaning to 19 days post weaning in 78 piglets. The expression of expressed marker genes was determinate by one-step quantitative real-time (qRT-PCR): TNFα, NFκB as pro-inflammatory; IL10, as anti-inflammatory; caspase 3 as apoptosis; cyclin D1 as cell cycle marker; and nucleosome component histon H3 as reference gene.

The feeding regimens result in tissue individual regulation of mRNA gene expression in all investigated organs. It was discovered that there were significant differences between the applied diets and significant changes during feeding time curse. Both pomace treatments caused a significant up-regulation of all investigated genes in liver. The effect on mesenterial lymph nodes and spleen was not prominent. In the GIT, the treatment groups showed a inhibitory effects on gene expression mainly in stomach and jejunum (NFκB, cyclin D1 and caspase 3). In colon the trend of caspase 3 was positive with the greatest change in the RWPD group.

In jejunum and stomach the cell cycle turn over was reduced, whereas in liver the cell turn over was highly accelerate. The influence on inflammatory marker gene expression is mainly relevant in stomach. It is presume that both flavanoid rich feeding regimens have the potential to modulate the mRNA expressions of inflammatory, proliferation and apoptotic marker genes in the GIT and piglet organs.

Sows housed in groups have to move through their pen to fulfil their behavioural and physiological needs such as feeding and resting. In addition to causing pain and discomfort, lameness may restrict the ability of sows to fulfil such needs. The aim of our study was to investigate the extent to which the mobility of sows is affected by different degrees of lameness. Mobility was measured as the sow’s willingness or capability to cover distances. Feed-restricted hybrid sows with different gait scores were subjected to a feed reward collection test in which they had to walk distances to obtain subsequent rewards. In all, 29 group-housed sows at similar gestation stage (day 96.6±7 s.d.) were visually recorded for gait and classified as non-lame, mildly lame, moderately lame or severely lame. All sows received 2.6 kg of standard commercial gestation feed per day. The test arena consisted of two feeding locations separated from each other by a Y-shaped middle barrier. Feed rewards were presented at the two feeders in turn, using both light and sound cues to signal the availability of a new feed reward. Sows were individually trained during 5 non-consecutive days for 10 min/day with increasing barrier length (range: 0 to 3.5 m) each day. After training, sows were individually tested once per day on 3 non-consecutive days with the maximum barrier length such that they had to cover 9.3 m to walk from one feeder to the other. The outcome variable was the number of rewards collected in a 15-min time span. Non-lame and mildly lame sows obtained more rewards than moderately lame and severely lame sows (P<0.01). However, no significant difference was found between non-lame and mildly lame sows (P=0.69), nor between moderately lame and severely lame sows (P=1.00). This feed reward collection test indicates that both moderately lame and severely lame sows are limited in their combined ability and willingness to walk, but did not reveal an effect of mild lameness on mobility. These findings suggest that moderately and more severely lame sows, but not mildly lame sows, might suffer from reduced access to valuable resources in group housing systems.

Components of reproductive efficiency of Zebu-type and Charolais × Zebu-type (1/2, 3/4 and 7/8) females were compared. Zebus had longer mean intervals from calving to first service (57·8 days) and from calving to conception (46·0 days). Least squares means for both traits were respectively 129·8 and 145·1 days. Correspondingly, in the Charolais cross group 26·4% more cows were detected in oestrus within 180 days of calving, and 31·4% more conceived in the same period. Least squares means for these traits were respectively 80·7 and 50·5%.

No significant differences were found between the two breeding types either in number of services per conception or in the percentage conceiving by artificial insemination (of those showing oestrus) both for lactating and dry females. A higher percentage of oestrus cycles of normal duration was found in Charolais cross (72·9 %) than in Zebus (63·1%). Gestation lengths of Zebus (Indu-Brasil sires) and Charolais cross (Charolais and Simmental sires) were respectively 288·8 and 283·1 days.

The main difference between breed types was the longer lactation anoestrus shown by Zebus. These were very sensitive to seasonal effects, showing a cyclical time trend with peaks of shorter anoestrous periods for cows calving in January–February–March, and longer ones for cows calving in July–August–September. Related traits followed parallel cycles. Charolais cross cows showed less variation than Zebus.

This study examined the effect of long-term selection of a maternal rabbit line, solely for a reproductive criterion, on the ability of female rabbits to deal with constrained environmental conditions. Female rabbits from generations 16 and 36 (n=72 and 79, respectively) of a line founded and selected to increase litter size at weaning were compared simultaneously. Female rabbits were subjected to normal (NC), nutritional (NF) or heat (HC) challenging conditions from 1st to 3rd parturition. Animals in NC and NF were housed at normal room temperatures (18°C to 25°C) and respectively fed with control (11.6 MJ digestible energy (DE)/kg dry matter (DM), 126 g digestible protein (DP)/kg DM, and 168 g of ADF/kg DM) or low-energy fibrous diets (9.1 MJ DE/kg DM, 104 g DP/kg DM and 266 g ADF/kg DM), whereas those housed in HC were subjected to high room temperatures (25°C to 35°C) and the control diet. The litter size was lower for female rabbits housed in both NF and HC environments, but the extent and timing where this reduction took place differed between generations. In challenging conditions (NF and HC), the average reduction in the reproductive performance of female rabbits from generation 16, compared with NC, was −2.26 (P<0.05) and −0.51 kits born alive at 2nd and 3rd parturition, respectively. However, under these challenging conditions, the reproductive performance of female rabbits from generation 36 was less affected at 2nd parturition (−1.25 kits born alive), but showed a greater reduction at the 3rd parturition (−3.53 kits born alive; P<0.05) compared with NC. The results also showed differences between generations in digestible energy intake, milk yield and accretion, and use of body reserves throughout lactation in NC, HC and NF, which together indicate that there were different resource allocation strategies in the animals from the different generations. Selection to increase litter size at weaning led to increased reproductive robustness at the onset of an environmental constraint, but failure to sustain the reproductive liability when the challenge was maintained in the long term. This response could be directly related to the short-term environmental fluctuations (less severe) that frequently occur in the environment where this line has been selected.

The effects of experimental Trypanosoma congolense infection on the digestive physiology and nutrient utilization in Gobra zebu and N'Dama cattle were examined in a 16-week trial. A pair-feeding procedure permitted examination of the effects of both food intake and trypanosomosis infection. Twenty Gobra and 16 N'dama bulls aged between 1 and 2 years were paired on a live-weight basis within each breed. One of each pair was chosen at random to serve as an uninfected control while the other was inoculated intradermally with 104 T. congolense in mice blood in the 6th week of the experiment. Packed cell volume and parasitaemia data were collected weekly throughout the trial. Total dry-matter intake (TDMI) and live-weight changes were measured weekly in all animals during the 16-week trial. Rate of passage (RoP) and dry matter digestibility were evaluated before and after infection.

While infection significantly depressed TDMI in both breeds (P < 0·05), neither infection nor breed affected the RoP and the apparent digestibility of the dry matter. Significant changes in live weight attributable solely to the infection were observed in both breeds. Loss of body weight was more severe (P < 0·05) in infected Gobra bulls compared with N'dama bulls possibly implying a superior efficiency of nutrient utilization by the N'dama during infection. In the course of the trial, one N'dama and three Gobra bulls that presented severe clinical symptoms of trypanosomosis were treated and withdrawn from the experiment along with their pair-fed controls.

In conclusion, the RoP and the digestive efficiency were not affected by infection and breed differences. Also, the trypanotolerance mechanism does not seem to be affected by anorexia but rather by the ability to conserve body reserves during infection.

A 4 × 4 Latin square design experiment with 3-week experimental periods was conducted with four wether sheep, each fitted with a permanent rumen cannula, to evaluate the effects of dietary protein sources and levels on fermentation and microbial activity in the rumen. Four complete diets were offered each containing (g/kg dry matter (DM)) molasses 248, grass silage 200 and barley straw 260. The control diet (C) also contained barley and soya-bean meal and the other three diets were supplemented with urea (CU), soya-bean meal (CS), and soya-bean meal and fish meal (CSF), respectively. This gave foods of similar concentrations of metabolizable energy (ME) and estimated fermentable ME (10·6 and 9·8 MJ/kg DM, respectively), but different levels (g/kg DM) of estimated effective rumen degraded dietary protein (ERDP) and digestible undegraded protein (DUP) (ERDP/DUP, 84/17, 109/17, 116/38 and 119/54 for diets C, CU, CS and CSF, respectively).

No clinical symptoms of ill health in the animals due to the feeding of molasses were observed during the experiment. The average pH values of rumen liquors obtained at various sampling times post feeding for diets C, CU, CS and CSF were 6·40, 6·49, 6·62 and 6·47 (s.e.d. 0·06 P < 0·05) respectively and average ammonia-nitrogen concentrations were 63, 81, 90 and 113 mg/l (s.e.d. 14·9, P < 0·02) respectively. The average concentrations of total volatile fatty acids in the rumen liquor were similar across the four treatments. The molar proportions of propionate and butyrate were higher for the diet C than for the other three diets (P < 0·05), while acetate was lower (P < 0·05). Supplementing with true protein (P < 0·05), but not with urea (P > 0·05), increased the molar proportions of isobutyrate and isovalerate. Whole tract apparent digestibilities of DM and organic matter did not differ significantly across the four treatments, but neutral-detergent fibre apparent digestibility (0·677, 0·672, 0·716 and 0·728 (s.e.d. 0·017) g/kg DM for diets C, CU, CS and CSF respectively) and the proportions of hay DM that disappeared in the rumen during 24 h incubation (0·223, 0·238, 0·284 and 0·271 (s.e.d. 0·019) g/kg DM) were significantly lower for diets C and CU than CS and CSF (P < 0·05). Urinary excretion of purine derivative nitrogen was similar across the four treatments. The results obtained from the present study indicate that there were no significant differences in the microbial crude protein synthesis in the rumen when a diet containing molasses was supplemented with urea or true protein. However, the supplementation of this control diet with true protein, but not with urea, did stimulate the degradation of hay DM in the rumen and the digestion of dietary fibre in the whole tract.

Due to the structure of the placenta in the horse (epitheliochorial) and the as yet un-activated immune system of the foal at birth, the transfer of maternal immunoglobulin G (IgG) is essential in the protection of the young foal until its own immune system develops. The fluidity of intestinal cell membranes may affect the transfer of IgG by receptor mediated endocytosis. In the present experiment we studied the effect of the addition of supplements rich in either alpha-linolenic acid or oleic acid to the diet of the mares starting 1·5 months before foaling and for 1 month after foaling on the passive transfer of IgG and the fatty acid composition of mammary secretions and plasma of foals. Twenty-six mares were allocated to one of two treatment groups (L: linseed supplement, no. = 13 and R: rapeseed supplement, no. = 13) according to date of foaling and live weight to produce two homogeneous groups. Mammary secretions were collected to measure IgG and fatty acid composition. Jugular blood samples were taken from the foals at time 0, 12 h, 24 h, 48 h, 1 week, 2 weeks, 3 weeks and 4 weeks after foaling to measure the concentration of IgG. A subsample of foals was used to measure the IgG absorption coefficient and the plasma fatty acid compositon. There was no effect of dietary treatment on the length of gestation, the production and transfer of IgG. Group L mares produced mammary secretions which were richer in C18: 3 and poorer in C18: 1 than group R mares (P < 0·001). Contrary to expectations the C18: 3 content of blood from foals at birth from both dietary treatments was very low and there was no difference between dietary groups. The percentage of C18: 3 and C18: 2 in fatty acids increased in foal blood only after sucking had occurred, with a difference between dietary groups (L > R). In addition, the percentages of C20: 3 and C20: 4 were higher in the foals at birth than 48 h later (P < 0·001) and at birth they were highest in the R group compared with the L group foals (P < 0·05 and P 0·10, respectively). In conclusion, the attempt to increase the supply of C18: 3 during gestation to foals and to improve the transfer of IgG post partum did not appear to succeed, perhaps because the foal uses C22: 6 (produced from C18: 3) for brain growth.

Camera-based systems in dairy cattle were intensively studied over the last years. Different from this study, single camera systems with a limited range of applications were presented, mostly using 2D cameras. This study presents current steps in the development of a camera system comprising multiple 3D cameras (six Microsoft Kinect cameras) for monitoring purposes in dairy cows. An early prototype was constructed, and alpha versions of software for recording, synchronizing, sorting and segmenting images and transforming the 3D data in a joint coordinate system have already been implemented. This study introduced the application of two-dimensional wavelet transforms as method for object recognition and surface analyses. The method was explained in detail, and four differently shaped wavelets were tested with respect to their reconstruction error concerning Kinect recorded depth maps from different camera positions. The images’ high frequency parts reconstructed from wavelet decompositions using the haar and the biorthogonal 1.5 wavelet were statistically analyzed with regard to the effects of image fore- or background and of cows’ or persons’ surface. Furthermore, binary classifiers based on the local high frequencies have been implemented to decide whether a pixel belongs to the image foreground and if it was located on a cow or a person. Classifiers distinguishing between image regions showed high (⩾0.8) values of Area Under reciever operation characteristic Curve (AUC). The classifications due to species showed maximal AUC values of 0.69.

Seventy-two pigs between 7 and 28 days of age were given diets containing milk, fish or soya bean proteins in two separate experiments. In the first experiment, the weight gains of pigs given casein, isolated soya bean protein, fish meal and soya bean meal were 211,180,200 and 191 g/day, respectively, and the food conversion ratios were 0·84, 1·16, 0·93 and 1·10, respectively.

In the second experiment, the protein sources were skim milk, casein, isolated soya bean protein, soya bean concentrate and soya bean meal; weight gains of the pigs on these respective diets were 205, 180, 154, 133 and 169 g/day, and the food conversion ratios were 0·81, 0·92, 0·97, 1·07 and 1·05.

Apparent digestibilities of the soya bean and fish protein diets were less than those of milk protein diets. Apparent digestibilities of all diets increased between the collection periods at 9 to 14 days and 23 to 28 days of age.

Effective tools for male contraception are important in the control of reproduction in animal populations. The aim of the present study was to evaluate the effects of active immunization against gonadotropin-releasing hormone (GnRH) on male reproductive function assessing testicular morphological changes and serum-gonadotropin levels in pre-pubertal rabbits, guinea pigs and ram lambs. An anti-GnRH vaccine was developed by linking a GnRH-homologous molecule to a tetanus clostridial toxoid (Al(OH)3 coadjuvant). After vaccination protocols testicular morphometry, histopathological alterations and endocrine responses (FSH, LH, testosterone and cortisol serum levels) were evaluated. Testicular volume was significantly reduced in vaccinated animals with respect to the control group in rabbits, guinea pigs and ram lambs (P<0.05 to P<0.001). The anti-GnRH vaccine generated a reduction in testicular volume of 15-, 27- and 11-fold, respectively. Tubule diameters decreased in the vaccinated group with respect to the control ~2.0-, 1.2- and 3.5-fold, respectively (P<0.001). Tubule, intertubular and lumen volumes significantly decreased in vaccinated rabbits (P<0.05), guinea pigs and ram lambs (P<0.01). Vaccinated animals of the three species showed significant reductions in spermatogonial numbers (10- to 40-fold; P<0.01). Sperm was absent in all seminiferous tubules of all rabbits, and most individuals of guinea pigs (80%) and ram lambs (60%). No significant differences were observed between vaccinated and control groups regarding FSH and LH during the experiments in the three experimental species/models used. Testosterone, however, was only significantly lower (~22-fold, P<0.01) in vaccinated rabbits. In conclusion, the present study demonstrated that pre-pubertal active immunization against GnRH leads to endocrine disruption and marked differences on testicular morphometry, development and activity among lagomorphs, hystricomorphs and ovine species with species-specific sensitivity regarding the anti-GnRH immune response.

Norwegian Red bulls, selected in Norway, have been used for crossbreeding with Israeli Holstein on commercial farms. The aim of this project was to investigate Norwegian Red×Israeli Holstein (NRX) performance to see how the daughters perform in a different environment than the one their sires were selected in. This was done by comparing health and fertility of NRX with their Israeli Holstein (HO) counterparts. The data consisted of 71 911 HO records and 10 595 NRX records from 33 855 cows in 23 Israeli dairy herds. Calving events took place between 2006 and 2016. Five postpartum disorders (mean frequency in HO v. NRX, %) recorded by veterinarians were analyzed: anestrus (37.4 v. 41.2), metritis (40.1 v. 28.6), ketosis (11.9 v. 7.1), lameness (7.1 v. 3.1) and retained placenta (6.2 v. 4.0). The incidence of abortions was also analyzed; HO had a mean frequency of 9.9% and NRX 8.2%. These traits were defined as binary traits, with ‘1’ indicating that the disorder was present and a treatment took place at least once, or ‘0’ if the cow did not show signs of that disorder. Days open (i.e. the number of days from calving to conception), body condition score (BCS) recorded on a 1 to 5 scale and changes in BCS from calving to peak lactation were also analyzed. A logistic model was used for the health traits, while days open and BCS were analyzed with linear models. The model included breed group, herd-year of calving, birth year and parity as fixed effects. There was a significantly higher risk (odds ratio for HO v. NRX in parentheses) of ketosis (1.46), metritis (1.78), lameness (2.07), retained placenta (1.41) and abortion (1.13) in HO compared with NRX. Israeli Holstein heifers and cows in parity 3 to 6 had fewer cases of anestrus than NRX but no differences were found between the groups in parities 1 and 2. Body condition score was higher for NRX than HO and there was less change in BCS from calving to peak lactation in NRX compared with HO. Likewise, NRX had fewer days open than HO. Results indicate that crossbreeding can produce cows with better fertility that are less susceptible to postpartum disorders.

Forty-eight castrate male and female Suffolk cross Mule lambs were used in a 2 × 2 factorial experiment to investigate the effect of autumn shearing and sex on growth performance over 46 days before slaughter. Lambs were penned individually outdoors and given pelleted lucerne ad libitum.

Shearing increased average food intake by 0·072 (P<0·05), live-weight gain by 0·149 (P<0·01) and carcass weight by 0·058 (P<0·05). It is concluded that shearing is financially worthwhile in climatic conditions such as the present experiment.

The study examined the effects of physical form and harvest time of alfalfa silage on eating and ruminating activity and particle size distribution in feed boli, rumen content and faeces in dry cows. The alfalfa crop was harvested at two stages of growth (early: NDF 37%, late: NDF 44% in dry matter (DM)), and from each harvest, a chopped (theoretical cutting length: 19 mm) and an unchopped crop was ensiled in bales. The silages were fed restrictively to four rumen cannulated non-lactating Jersey cows (391 ± 26 kg) in a 4 × 4 Latin square design. The cows were fed restrictively 80% of their ad libitum intake twice daily. Chewing activity was recorded for 96 h continuously. Swallowed boli, rumen content, rumen fluid and faeces samples were collected, washed in nylon bags (0.01 mm pore size) and freeze-dried before dry sieving through 4.750, 2.360, 1.000, 0.500 and 0.212 mm pore sizes into six fractions. The length (PL) and width (PW) of particles within each fraction was measured by the use of image analysis. The eating activity (min/kg dry matter intake (P < 0.01) and min/kg NDF (P < 0.05)) was affected by harvest time. The mean ruminating time (min/kg DM) was affected by harvest time (P < 0.01), physical form (P < 0.05) and NDF intake per kg BW (P < 0.01). The proportion of washed particle DM of total DM in boli, rumen content, rumen fluid and faeces was affected by harvest time (P < 0.01) and highest by feeding late-harvested alfalfa silage. Two peaks on the probability density distribution function (PDF) of PW and PL values of boli, rumen content and faeces were identified. Chopping of the silage decreased the mean PL and PW, the most frequent PL (mode) and 95% percentile PL and PW values in boli. In the rumen content, chopping increased the mean PW (P < 0.05). The dimension sizes of faeces particles were not significantly affected by chopping. The mode PW value was lower in rumen content and faeces than in boli (P < 0.001), and the mode PL value was higher in boli and lower in faeces compared with rumen contents (P < 0.001). In conclusion, the mean total chewing activity per kg NDF decreased due to chopping and early harvest time. The mean PL and PW in boli decreased due to chopping and late harvest. The two peak values on the PDF (PL) and PDF (PW) of boli, rumen content and faeces particles are most likely related to the leaf and the stem residues.

The release rate (RR) of sulphur hexafluoride (SF6) gas from permeation tube in the rumen appears to be positively related with methane (CH4) emissions calculated using the SF6 tracer technique. Gas samples of breath and ruminal headspace were collected simultaneously in order to evaluate the hypothesis that transactions of SF6 in the rumen are the source for this relationship. Six non-lactating dairy cows fitted with rumen cannulae were subdivided into two groups and randomly assigned to a two-period crossover design to permeation tubes with low RR (LRR = 1.577 mg/day) or two-times higher RR (HRR = 3.147 mg/day) RR. The cows were fed limited amounts of maize silage (80% ad libitum) split into two meals (40% at 0800 h and 60% at 1600 h). Each period consisted of 3-day gas sampling. Immediately before the morning feed and then each hour over 8 h, ruminal gas samples (50 ml) were withdrawn through the cannula fitted with stoppers to prevent opening. Simultaneously, 8-h integrated breath gas samples were collected over the same period. Ratios of concentration of CH4/SF6, CO2/SF6 and CO2/CH4 and emission estimates of CH4 and CO2 were calculated for each sample source using the SF6 tracer technique principles. The LRR treatment yielded higher (P < 0.001) ruminal CH4/SF6 (by 1.79 times) and CO2/SF6 (by 1.90 times) ratios than the HRR treatment; however, these differences were lower than the 2.0 times difference expected from the RR between the LRR and HRR. Consequently, the LRR treatment was associated with lower (P < 0.01) ruminal emissions of CH4 over the 8-h collection period than with the HRR treatment (+11%), a difference also confirmed by the breath samples (+11%). RR treatments did not differ (P = 0.53) in ruminal or breath CO2 emissions; however, our results confirm that the SF6 tracer seems inappropriate for CO2 emissions estimation in ruminants. Irrespective of the RR treatment, breath samples yielded 8% to 9% higher CH4 emission estimates than the ruminal samples (P = 0.01). The relationship between rumen and breath sources for CH4 emissions was better for LRR than for HRR treatment, suggesting that tracer performance decreases with the highest RR of SF6 tested in our study (3.1 mg/day). A hypothesis is discussed with regard to the mechanism responsible for the relationship between RR and CH4 emission estimates. The use of permeation tubes with small range in RR is recommended in animal experiments to decrease variability in CH4 emission estimates using the SF6 tracer technique.

Two fibrous roughages, wheat straw (WS) and cotton hulls (CH), were either untreated or treated with 30 g/kg or 60 g/kg of sodium hydroxide (NaOH), the residual NaOH was either unneutralized or neutralized with sulphuric acid, and the materials were then pelleted. The effects of these treatments on the nutritive value of the two roughages were examined in an arrangement that differed from the factorial 2 × 3 × 2 = 12 in that only one control group was included for each roughage. Digestibility trials, in vitro and in vivo, and a 7-month feeding trial were carried out. Concentrates were limited in the feeding trial to 6 kg/head per day, and roughages were offered ad libitum.

Dry matter digestibility in vitro was significantly higher on CH than on WS and was significantly increased by NaOH treatment. Level of NaOH and neutralization of residual alkali had no significant effect. Intake of WS was increased by treatment with 30 g NaOH/kg in the digestibility and feeding trials. Increasing the level of NaOH to 60 g/kg reduced intake of both roughages. Digestibility of organic matter of WS was increased by NaOH treatment at both levels, by 25 to 30%, while that of CH was improved significantly only by the higher level. Neutralization had no effect. The actual intake of roughages was 30 to 35% of the entire ration. The rate of gain of animals offered roughages treated with 30 g NaOH/kg was non-significantly increased, and that of animals offered roughages treated with 60 g NaOH/kg was reduced significantly in comparison with the control. Animals offered NaOH-treated roughages had a significantly higher dressing percentage, and those offered treated WS had a greater fat trim than the control animals. Efficiency of conversion of metabolizable energy into live or carcass weight for both roughages was improved only with the neutralized 30 g NaOH/kg treatment. Comparing the performance in this study with that of a former study of similar design in which the same roughages were offered wet, revealed no marked advantage from pelleting.

In recent years, livestock producers have been supplementing animal diets with fish meal (FM) to produce value-added products for health conscious consumers. As components of FM have unique neuroendocrine–immunomodulatory properties, we hypothesize that livestock producers may be influencing the overall health of their animals by supplementing diets with FM. In this study, 40 pregnant ewes were supplemented with rumen protected (RP) soybean meal (SBM: control diet) or RP FM, commencing gestation day 100 (gd100), in order to evaluate the impact of FM supplementation on the innate and acquired immune response and neuroendocrine response of sheep during pregnancy and lactation. On gd135, half the ewes from each diet (n = 10 FM, n = 10 SBM) were challenged iv with lipopolysaccharide (LPS) to simulate a systemic bacterial infection and the febrile, respiratory and neuroendocrine responses were monitored over time; the other half (n = 10 FM, n = 10 SBM) of the ewes received a saline injection as control. On lactation day 20 (ld20), all ewes (n = 20 FM, n = 20 SBM) were sensitized with hen egg white lysozyme (HEWL) and the serum haptoglobin (Hp) response was measured over time. The cutaneous hypersensitivity response (CHR) to HEWL challenge was measured on ld30 (n = 20 FM, n = 20 SBM), and blood samples were collected over time to measure the primary and secondary immunoglobulin G (IgG) response to HEWL. There was an attenuated trend in the LPS-induced febrile response by the FM treatment when compared with the SBM treatment (P = 0.06), as was also true for the respiratory response (P = 0.07), but significant differences in neuroendocrine function (serum cortisol and plasma ACTH) were not observed between treatments. Basal Hp levels were significantly lower in the FM supplemented ewes when compared with the SBM supplemented ewes (P < 0.01), and the Hp response to HEWL sensitization differed significantly over time between treatments (P < 0.01). The CHR to HEWL was also significantly attenuated in the FM treatment compared with the SBM (P < 0.01); however, treatment differences in the primary and secondary IgG responses to HEWL were not observed. These results indicate that FM supplementation differentially affects the innate and acquired immune responses in pregnant and lactating sheep compared with a typical SBM diet of commercial flocks. The long-term implications of this immunomodulation warrant further investigation.