Different doses of chromium propionate in the nutrition of pregnant ewes and their effects on their offspring.

Performance and behavior of the progeny of ewes fed with different sources and energy feed

This study aimed to evaluate the inclusion of chromium propionate or calcium salts of palm oil in ewes' diet during the final third of gestation and lactation on progeny performance, carcass characteristics, non-carcass components, and bone density. Forty-three ewe, Santa Inês and Dorper breed, three ± one-year-old, and body weight 57 ± 10 kg were used. The experimental design was in casual blocks in three treatments, CTL treatment (n = 15) with starch from corn; CR (n = 15) diet CTL plus chromium propionate; PF (n = 13) diet CTL plus calcium salts of palm oil. After weaning, 23 male lambs from these ewes were confined in individual stalls, with the same diet for 60days, slaughtered. The data were analyzed using the SAS program, PROC GLM, and compared the means using Tukey's test at 5% probability. The maternal diet did not alter the dry matter intake, feeding efficiency, and average daily weight gain. Therefore, weights (weaning and slaughter) and carcass yield were higher for CR and PF groups than for CTL (P < 0.05). The treatment did not influence the loin eye area and fat thickness (P > 0.05). The spleen and the respiratory tract were smaller for PF and larger for CTL (P < 0.05). Leg weight was higher for CR. The perimeter and depth of the shank for the CR and PF lambs were higher, indicating an effect of maternal nutrition in this commercial cut. The CR group had a smaller epiphysis measurement and femur length than the CTL group. We concluded that the fetal programming effect in ewes fed with Cr propionate and Ca salts of palm oil benefited the progeny by increasing their body weight, better carcass yield, and a higher proportion of prime cuts.

Means of assessing the adequacy of nutrition of pregnant ewes

Reducing the level of nutrition of twin-bearing ewes during mid to late pregnancy produces leaner prime lambs at slaughter

Effects of maternal nutrition on udder development during late pregnancy and on colostrum production in Scottish Blackface ewes with twin lambs

The accurrate diagnosis of pregnancy and prediction of lambing rate are important tools that ensure the proper nutrition of pregnant ewes, optimize the birth weight of offspring and decrease the occurrence of pregnancy toxemia in sheep production. In this study, it was aimed to evaluate the reliability of the rapid visual PAG ELISA test in predicting the lambing rate, when performed in two different stages of pregnancy in Awassi sheep. A total of 210 ewes, belonging to a commercial flock, were assigned to two groups according to their mating date. Group 1 comprised 120 ewes, which were in the period from 28 to 38 days post-mating, and Group 2 comprised 90 ewes, which were in the period from 40 to 59 days post-mating. The rapid visual PAG ELISA test was performed on the serum samples of the ewes, according to the manufacturer’s instructions. The diagnostic test characteristics of the rapid visual PAG ELISA test were assessed for the prediction of lambing rate, using the lambing records as a gold standard. The sensitivity, specificity, positive predictive value, negative predictive value, and accuracy of the rapid visual PAG ELISA test were 95.79%, 52.38%, 90.10%, 73.33%, and 87.93%, respectively, in G1 and 92.75%, 70.00%, 91.43%, 73.68%, and 87.64%, respectively, in G2. The McNemar analysis showed that there was no difference between the rapid visual PAG ELISA test and lambing records in the two groups. Eighty per cent all of the ewes exposed to rams lambed. While the rapid visual PAG ELISA test predicted that 83.4% of the ewes exposed to rams would lamb, in reality it achieved that 75.6% of them lambed. The differences between the predicted and achieved lambing rates of rapid visual PAG ELISA (7.8%) indicate embriyonic/fetal mortality. The results of this study indicated that the lambing rate can be predicted with a high sensitivity from the 28th day of pregnancy, using the rapid visual PAG ELISA test.

Animal welfare and sustainability of production under extensive conditions—A European perspective

Nutrition of the pregnant ewe

Three experiments were conducted to evaluate interrelationships between S, Se and vitamin E in the nutrition of the ovine. In the initial experiment, a daily intake of 7.62 gm. S as sodium sulfate was found to be readily absorbed and excreted in large quantities (51.4% of ingested S) in the urine. The amount of water excreted via the urine was found to be greatly increased due to sulfate supplementation of the ration. Hence sodium sulfate was considered an excellent source of S as a potential competitor with Se in nutrition of the pregnant ewe. Hematocrits of ewes at 27–38 days prepartum appeared to be greater when ewes were fed a final level of 12.1 gm. S per head daily than when fed 3.0 or 21.3 gm. per head daily. The hematocrits of ewes fed 3.0 or 21.3 gm. S per head daily appeared to be below normal. Serum tocopherol levels were significantly affected by treatment and dietary Se depressed levels in what may have been a sparing action of Se in mobilizing tissue tocopherols. Serum tocopherol levels appeared to be increased as a result of feeding the intermediate level of S (final level, 12.1 gm. per head daily). Administration of vitamin E at 89 days or less of pregnancy appeared to exert a favourable effect on lambing percentage; the intermediate level of S also appeared to exert a favourable effect, but this was primarily a result of the 190% lamb crop that resulted when the ewes also were administered tocopherol. Five ewes fed the intermediate level of S and four fed the high level aborted in late pregnancy. These abortions occurred regardless of vitamin E or Se administration. Pathological changes in tissues of five lambs from ewes fed medium and high levels of sulfur were similar to those associated with WMD. There was no evidence that 0.75% to 1.32% dietary S in rations fed to ewes during late pregnancy were contributory to WMD in lambs born alive and surviving beyond 24 hr. of age. Administration of 1.5 mg. Se to 2- to 4-week old lambs creep fed diets containing less than 0.07 ppm Se and nursing ewes fed rations providing an equally low level of Se did not significantly increase gains over a 6 5-day feeding period.

The nutrition of grazing, pregnant crossbred ewes was managed so that from 6-15 and from 15-20 weeks of pregnancy, ewes were offered either high (H) or low (L) quality and quantity of nutrition as provided by pasture. At one week prior to parturition, the ewes in each of the four treatment groups (HH, HL, LH, LL) were then placed onto good pasture for lambing. Differential nutrition during pregnancy significantly affected gestation length of the ewes, with HH ewes having the shortest gestation. By day 148, 1.6 times more HH ewes had lambed compared with the LL group ewes. Significant differences were observed in lamb birth weight5 with nutrition in the last trimester (15-20 weeks) having a greater influence on birth weight. This was particularly so for twins. There was no significant difference in the survival of the single lambs, but for twin lambs survival was lowest with the LL ewes. These results show the consequences of maintaining or altering nutrition of single- and twin-bearing ewes during pregnancy. Birth weight of twin-born lambs was most responsive. Apart from lambs of the LL group ewes, the weaning weights of surviving lambs were largely unaffected by prenatal nutrition to one week prepartum.

Perinatal mortality reduces the number of lambs sold per ewe and consequently impacts negatively on the economic sustainability of sheep farming. Figures quoted for the incidence of perinatal lamb mortality...

Our objective was to explore diet selection and productive performance by sheep during peripartum. Pregnant Saint-Croix and Katahdin ewes were housed in individual pens from 100 days of gestation to 60 days of lactation and assigned to two groups: Free-choice-FC and Mixed-ration-MR (n = 12/group). Sheep in FC received ad-libitum amounts of soybean meal, sorghum grain, alfalfa and oat hays, presented in individual troughs. Animals in MR received a total-mixed-ration with these feeds, balanced for gestation or lactation according to NRC. Dry matter (and nutrient) intake/kg BW was measured daily, whereas BW and BCS were measured every 7 and 14 d, respectively. Data was analyzed as a Linear Mixed Model with repeated measures; group, breed, litter size (single, twins) and parity (primiparous, multiparous) were the fixed factors and sheep (random factor) was nested within group. Overall dry matter and ME intake did not differ between groups (P &amp;gt; 0.05), without breed, litter size or parity effects (P &amp;gt; 0.05), but protein intake was greater and NDF and ADF intakes were lower in FC than in MR (P &amp;lt; 0.001). During gestation, FC sheep consumed soy=alfalfa &amp;gt;sorghum &amp;gt;oats, and during lactation they increased (2X) soy intake (P &amp;lt; 0.001). Body weight was similar between groups (73.3±1.3, and 70.6±1.3 kg, for FC and MR, respectively; P=0.148), whereas BCS was greater for FC than for MR (3.9±0.2 vs. 3.3 ±0.1; P = 0.01). During lactation, ewe BW (67.3±1.3 vs. 61.92±1.3 kg; P = 0.01) and BCS (3.83±0.1 vs. 3.03±0.1; P &amp;lt; 0.001) were greater for FC than for MR. Offspring BW was similar between groups (11.5±0.6, and 11.4±0.5 kg, for FC and MR, respectively; P = 0.804). In conclusion, the free-choice treatment enhanced ewe nutrition, reducing BW and BCS losses during lactation without influencing offspring growth. Free-choice may enable ewes to meet their individual nutrient needs, with benefits to their welfare and postpartum ovarian activity.

Faces are highly emotive stimuli and we find smiling or familiar faces both attractive and comforting, even as young babies. Do other species with sophisticated face recognition skills, such as sheep, also respond to the emotional significance of familiar faces? We report that when sheep experience social isolation, the sight of familiar sheep face pictures compared with those of goats or inverted triangles significantly reduces behavioural (activity and protest vocalizations), autonomic (heart rate) and endocrine (cortisol and adrenaline) indices of stress. They also increase mRNA expression of activity-dependent genes (c-fos and zif/268) in brain regions specialized for processing faces (temporal and medial frontal cortices and basolateral amygdala) and for emotional control (orbitofrontal and cingulate cortex), and reduce their expression in regions associated with stress responses (hypothalamic paraventricular nucleus) and fear (central and lateral amygdala). Effects on face recognition, emotional control and fear centres are restricted to the right brain hemisphere. Results provide evidence that face pictures may be useful for relieving stress caused by unavoidable social isolation in sheep, and possibly other animal species, including humans. The finding that sheep, like humans, appear to have a right brain hemisphere involvement in the control of negative emotional experiences also suggests that functional lateralization of brain emotion systems may be a general feature in mammals.

Although chromium (Cr) feeding study results have been variable, our hypothesis was feeding a regimen that changed dosage over time would result in a larger positive response in growth performance and carcass characteristics. In Exp. 1, a total of 1,206 pigs (PIC 337 × 1050, initial BW 28.7 kg) were used with 27 pigs per pen and 9 pens per treatment. Diets were corn–soybean meal-dried distillers grains with solubles based and were fed in a five-phase feeding program. Treatments were arranged as a 2 × 2 + 1 factorial with a control diet containing no added Cr propionate (Kemin Industries Inc., Des Moines, IA), or diets with either 100 or 200 µg/kg added Cr during the grower (dietary phases 1 and 2) and/or finisher (dietary phases 3, 4, and 5) periods. During the grower period, ADG and G:F were similar among pigs fed the control or 100 µg/kg added Cr diets, but decreased in pigs fed 200 µg/kg Cr (quadratic, P ≤ 0.001). During the finisher period, pigs supplemented with 200 µg/kg added Cr had the greatest ADG and G:F (quadratic, P ≤ 0.019). Overall, increasing Cr had no effect on ADG or ADFI; but G:F was greatest (quadratic, P = 0.020) when pigs were fed 100 µg/kg of added Cr throughout. Carcass characteristics were not influenced by Cr dosage or feeding regimen. In Exp. 2, a total of 1,206 pigs (PIC 359 × 1050, initial BW 48.9 kg) were used with 27 pigs per pen and 15 pens per treatment. Diets were corn–soybean meal, dried distillers grains with solubles based and were fed in four phases. There were three dietary treatments: a diet with no added Cr for both grower (dietary phase 1 and 2) and finisher (dietary phase 3 and 4) periods, a diet with 200 µg/kg added Cr during the grower and 100 µg/kg added Cr during the finisher periods, or a diet with 200 µg/kg added Cr for both periods. Addition of 200 µg/kg Cr in both periods marginally increased (P < 0.10) ADG compared with pigs fed no added Cr. There was no evidence (P ≥ 0.523) of added Cr influencing overall ADFI and G:F. Percentage carcass yield was reduced (P = 0.018) when Cr was added at 200 µg/kg for both periods, with no evidence of differences (P ≥ 0.206) in other carcass characteristics. In summary, overall G:F was improved in Exp. 1, and ADG in Exp. 2, by added Cr, but there was no evidence that different feeding regimens will consistently result in improved performance. However, these data are consistent with the literature in that added Cr in growing-finishing pigs diets improves, albeit small, ADG or G:F.

Foetal programming in sheep: Reproductive and productive implications