Publications

Eight species of forage, a cool-season perennial (tall fescue (Festuca arundinacea)) and annual grass (winter wheat (Triticum aestivum)), four warm-season perennial grasses (caucasian (Bothriochloa caucasica), plains (B. ischaemum), old world bluestem, bermudagrass (Cynodon dactylon), and eastern gamagrass (Tripsacum dactyloides)), a warm season annual (crabgrass (Digitaria sanguinalis)) and a perennial legume (alfalfa (Medicago sativa)), were each cut at two or three maturities to provide a wide array of quality difference (n=20). Twenty wether goats (Capra hicus) were fed the hays in four different trials using an incomplete block design so that four different goats received each hay. Alfalfa produced the highest (25gkg-1 body weight (BW)) and wheat the lowest (13.6gkg-1 BW) organic matter (OM) intake. A number of the grasses provided less than 20gkg-1 BW OM intake. Digestion of OM was also highest for alfalfa (>715gkg-1) and lowest for bermudagrass (508gkg-1). All measures and expressions of intake and digestibility were better related to ruminating and retention time than to forage chemistry, with the exception of crude protein digestibility. The best equations for predicting intake included a combination of mean retention time and forage acid detergent fiber (ADF) content (reciprocal and quadratic); that for digestibility included permanganate lignin (reciprocal), and the quadratic for ruminating and retention time. Equations for predicting the constraint on intake and digestible organic matter intake produced higher r2 than those for either intake or digestibility. Digestibility of ADF and neutral detergent fiber (NDF) were poorly predicted with either chemistry (r2<=0.20), or ruminating time (r2=0.43), but combinations of permanganate lignin content of NDF, retention and ruminating time produced reasonable equations.

Eight species of forage, a cool-season perennial (tall fescue (Festuca arundinacea)) and annual grass (winter wheat (Triticum aestivum)), four warm-season perennial grasses (caucasian (Bothriochloa caucasica), plains (B. ischaemum), old world bluestem, bermudagrass (Cynodon dactylon), and eastern gamagrass (Tripsacum dactyloides)), a warm season annual (crabgrass (Digitaria sanguinalis)) and a perennial legume (alfalfa (Medicago sativa)), were each cut at two or three maturities to provide a wide array of quality difference (n=20). Twenty wether goats (Capra hicus) were fed the hays in four different trials using an incomplete block design so that four different goats received each hay. Alfalfa produced the highest (25gkg−1 body weight (BW)) and wheat the lowest (13.6gkg−1 BW) organic matter (OM) intake. A number of the grasses provided less than 20gkg−1 BW OM intake. Digestion of OM was also highest for alfalfa (>715gkg−1) and lowest for bermudagrass (508gkg−1). All measures and expressions of intake and digestibility were better related to ruminating and retention time than to forage chemistry, with the exception of crude protein digestibility. The best equations for predicting intake included a combination of mean retention time and forage acid detergent fiber (ADF) content (reciprocal and quadratic); that for digestibility included permanganate lignin (reciprocal), and the quadratic for ruminating and retention time. Equations for predicting the constraint on intake and digestible organic matter intake produced higher r2 than those for either intake or digestibility. Digestibility of ADF and neutral detergent fiber (NDF) were poorly predicted with either chemistry (r2≤0.20), or ruminating time (r2=0.43), but combinations of permanganate lignin content of NDF, retention and ruminating time produced reasonable equations.

Three experiments were conducted to evaluate sunflower seed meal (SFM) as a substitute for soybean meal (SBOM) in rations of fattening Awassi lambs and milking ewes. In the first experiment, 12 Awassi lambs were assigned into four groups to measure the digestibility of the SFM and experimental rations. The control group ration (1) contained SBOM while in the other two rations, SFM replaced SBOM at a level of 50% (2) and 100% (3), respectively. The fourth group was fed only SFM. No significant differences were observed between lambs fed the experimental rations in digestibilities of DM, OM, CP, CF, NDF, ADF or N balance. NFE had a higher (P<0.05) digestibility for ration 1 than ration 2. In the second experiment, the voluntary feed intake was measured for the Awassi ewes during milking and dry period using 36 Awassi lactating ewes. For the two stages there were no significant differences between rations in voluntary intake. Milk yields (kg/herd per day), milk fat (%) and milk total solids (%) were not different among groups. In the third experiment, 42 lambs (males and females) were divided randomly into three treatment groups. Rations were the same experimental rations in the digestibility study. There were no significant differences in the average final BW, ADG and average feed conversion ratios (FCR) among the treatments. These experiments showed that SFM could replace SBOM as a protein source in rations of fattening Awassi lambs and milking Awassi ewes.

Three experiments were conducted to evaluate sunflower seed meal (SFM) as a substitute for soybean meal (SBOM) in rations of fattening Awassi lambs and milking ewes. In the first experiment, 12 Awassi lambs were assigned into four groups to measure the digestibility of the SFM and experimental rations. The control group ration (1) contained SBOM while in the other two rations, SFM replaced SBOM at a level of 50% (2) and 100% (3), respectively. The fourth group was fed only SFM. No significant differences were observed between lambs fed the experimental rations in digestibilities of DM, OM, CP, CF, NDF, ADF or N balance. NFE had a higher (P<0.05) digestibility for ration 1 than ration 2. In the second experiment, the voluntary feed intake was measured for the Awassi ewes during milking and dry period using 36 Awassi lactating ewes. For the two stages there were no significant differences between rations in voluntary intake. Milk yields (kg/herd per day), milk fat (%) and milk total solids (%) were not different among groups. In the third experiment, 42 lambs (males and females) were divided randomly into three treatment groups. Rations were the same experimental rations in the digestibility study. There were no significant differences in the average final BW, ADG and average feed conversion ratios (FCR) among the treatments. These experiments showed that SFM could replace SBOM as a protein source in rations of fattening Awassi lambs and milking Awassi ewes.

A total of 209 milk samples were collected from the udder halves of 178 native dairy ewes at 2 weeks after lambing until the 10th week postpartum. Those which were classified by bacterial culture and California Mastitis Test (CMT) as positive, were deemed to have glands with subclinical mastitis (SCM). The periodic prevalence rate of SCM was 39%. The most common bacterial isolates from SCM cases were coagulase negative staphylococci (41%), Bacillus cereus (33%), Staphylococcus aureus (22%) and Streptococcus spp. (4%). The mean activity of lactate dehydrogenase (LDH) and alkaline phosphatase (ALP) were higher in milk from SCM udders than in milk from healthy udders (P<0.01). There were no significant differences in blood serum LDH, ALP and aspartate aminotransferase (AST) of healthy and subclinical mastitic ewes. The increment in LDH and ALP in milk of udders shows the presence of tissue damage provoked by SCM. Thus, these parameters might be suitable for use in the early diagnosis of subclinical mastitis in ewes.

A total of 209 milk samples were collected from the udder halves of 178 native dairy ewes at 2 weeks after lambing until the 10th week postpartum. Those which were classified by bacterial culture and California Mastitis Test (CMT) as positive, were deemed to have glands with subclinical mastitis (SCM). The periodic prevalence rate of SCM was 39%. The most common bacterial isolates from SCM cases were coagulase negative staphylococci (41%), Bacillus cereus (33%), Staphylococcus aureus (22%) and Streptococcus spp. (4%). The mean activity of lactate dehydrogenase (LDH) and alkaline phosphatase (ALP) were higher in milk from SCM udders than in milk from healthy udders (P<0.01). There were no significant differences in blood serum LDH, ALP and aspartate aminotransferase (AST) of healthy and subclinical mastitic ewes. The increment in LDH and ALP in milk of udders shows the presence of tissue damage provoked by SCM. Thus, these parameters might be suitable for use in the early diagnosis of subclinical mastitis in ewes.

Susceptibility to IVM (IVM) of “strain A” Haemonchus contortus which had been exposed to IVM four times over a 2-year period was compared to IVM susceptibility of “strain C” H. contortus which had no prior field exposure to IVM, by in vivo and in vitro methods. In vivo, the percentage reduction in faecal egg counts (FEC) and the total worm counts (TWC) were compared between control animals (lambs and kids) and animals treated with low dose IVM (20μg/kg). In vitro susceptibility to IVM was evaluated by larval migration inhibition (LMI) after the two strains of H. contortus were exposed to different concentrations of IVM. The dose response, measured as the proportion of larvae inhibited from migrating, was used to estimate LD50. Although differences in response to IVM in the in vivo determinations were not significant, “strain A” H. contortus had a significantly higher LD50 than “strain C” in the LMI assay. Coincident with the conduct of the in vivo experiment, it was observed that “strain A” H. contortus established and survived better than “strain C” in the control lambs.

Resistance to naturally acquired gastro-intestinal (GI) nematode parasite infections (predominantly Haemonchus) of 212 Jamunapari and 163 Barbari goats (does) were studied in different physiological stages, namely pregnant, dry and lactating stages in a semi-arid region of India. The faecal egg counts (FECs) for GI nematode infections were examined in different physiological stages in both the breeds in two periods, i.e. an early period (October–November) and a late period (February–March). Analysis was carried out on loge(FEC+100) transformed data, accounting for repeated records on does, during early and late periods. Breed had significant effect on FEC in early and late periods in pregnant, dry and lactating does. Breed by physiological interaction had significant effect on FEC in both the early and late periods. Jamunapari lactating goats had significantly higher FEC than that of dry and pregnant does but there was no peri-parturient rise in FEC in the resistant Barbari goats.