Influence of Post-AI Nutrition on Blood Urea Nitrogen, Progesterone, and Pregnancy

Research has shown that changes in nutrition can have an effect on reproductive performance. Our objective was to determine the effect of post-AI nutrition on BCS, blood urea nitrogen (BUN), progesterone, and pregnancy rates. Forage-developed Angus-cross bred heifers (n = 336) were synchronized with the Select Synch+ Controlled Internal Drug Releasing device (CIDR) protocol (d -7 100 μg GnRH and CIDR; d 0 25 mg PG and removal of CIDR). Estrus was detected for 72 h and heifers bred by AI 12 h after being detected in estrus; heifers not in detected in estrus were bred by AI and given an injection of GnRH at 72 h. Each breeding period was equally divided into three treatments: 1) heifers returned to feedlot (LOT), 2) heifers were moved to pasture (PASTURE), or 3) heifers were moved to pasture and supplemented with 5 lb/hd/d of dried distillers grains plus solubles (SUPP). Blood samples were collected on d -7, 0, 2, 14 and 42 (pregnancy determination; d 0 = AI). Body condition scores were determined on d -7 and 42. All heifers were in similar BCS (5.4 ± 0.05) on d -7, but on d 42 SUPP (5.9 ± 0.04) were in better condition than LOT (5.8 ± 0.04) which were in better condition than PASTURE (5.4 ± 0.04). All treatments had similar BUN concentrations on d -7 (129 ± 1), but on d 2, 14, and 42 SUPP had greater BUN concentrations compared to both LOT and PASTURE. There was no difference in BUN concentrations between pregnant and open heifers. Progesterone concentrations were similar among all heifers on d 0 and 2. On d 14, SUPP had greater progesterone concentrations compared to LOT, and on d 14 and 42 PASTURE had greater progesterone concentrations compared to LOT. Progesterone was similar for open and pregnant heifers on d 0 and 2, but greater in pregnant heifers on d 14 and 42. There was no difference among treatments in pregnancy rates (57, 56, and 59% for SUPP, LOT, and PASTURE; analyzed by chi-square). In summary, supplementing forage-developed heifers after insemination increased BCS and BUN concentrations but had no effect on pregnancy rates

Reproductive Fertility in Herd Bulls

Herd bulls have a large influence on many aspects of beef operations, especially an operation’s profitability. For example, percent calf crop weaned is the single most important factor influencing profitability, and the number of cows bred during the breeding season plays the largest role in percent calf crop weaned. Therefore, an operation’s profitability is directly tied to the herd bull’s breeding ca¬pability. In addition, herd bulls supply half of the genetics to all the calves he sires; therefore, bull selection can be the most powerful method of genetic improvement in the herd. Herd bulls also influence overall herd fertility more than any other single animal; the loss of fertility by a bull can mean the potential loss of an entire calf crop. For the above reasons, and because greater than 90% of the beef cows in the United States are bred by natural service, it is important that bulls be managed to optimize breeding performance. There are several factors that influence bull fertil¬ity. First, the bull must have developed properly and have reached puberty to be fertile. Second, the bull’s physical characteristics, such as scrotal circumference, mating abil¬ity, and semen quality, play a role in his fertility. Third, the bull’s libido and social dominance influence his fertility

Bull Nutrition

Bull nutrition is often overlooked by many producers, except when problems arise. Bulls are often managed as one group even though there may be large differences in age, size, and body condition. Seedstock producers are the primary individuals managing the development program of bulls being sold. For commercial producers, feeding programs usually include feeding purchased bull(s) from delivery until the breeding season and bulls retained from one breeding season to the next. The debate over the correct method for developing bulls is not settled: Should you develop bulls at a moderate rate of gain? Or should you develop bulls on a ration that is capable of supporting high rates of gain so genetic differences can be measured for selection and marketing purposes? Bulls put into many bull test stations are placed on rations to support high rates of gain. Many seedstock producers have established specific feeding programs to fit the desired animal performance (where bulls show their genetic potential and are cost efficient)

Bull Management and Nutrition

Proper management and nutrition of bulls is essential to ensure cow/calf producers maximize reproductive efficiency and genetic improvement of the calf crop. In addition, the herd bull influences overall herd fertility more than any other single animal, and loss of fertility by a bull can cause substantial loss to a potential calf crop. Each cow produces one calf per year; however, bulls should contribute to the calf crop by 25 to 60 times via siring 25 to 60 calves. Additionally, bulls influence their daughters’ production in the cow herd. Therefore, bull selection can be the most powerful method of genetic improvement in the herd, but bulls with low fertility, structural problems and low libido reduce the percent calf crop weaned

Impact of Social Capital on Employment and Marriage among Low Income Single Mothers

The 1996 Personal Responsibility and Work Opportunity Reconciliation Act of 1996 (PRWORA, P. L. 104-93) called primarily on women to achieve two goals: work and/or marriage. For low income single mothers with limited access to capital, the PRWORA presents a quagmire in that the public safety nets previously guaranteed by the policies of the New Deal were abruptly supplanted by policies with obligations that require various forms of capital. Using longitudinal data from the Fragile Families and Child Wellbeing dataset, we examine the impact of social capital on the chances of marriage and employment among single, unemployed mothers. We find that social capital increases a woman\u27s chances of both marriage and stable employment, but the social capital must be expansive in order to challenge significant social disadvantage. We conclude with a discussion of the importance of social capital as a precursor to upward social mobility for low income mothers as opposed to simply getting \u27off of welfare.\u2

Bull Management and Nutrition

Proper management and nutrition of bulls is essential to ensure cow/calf producers maximize reproductive efficiency and genetic improvement of the calf crop. In addition, the herd bull influences overall herd fertility more than any other single animal, and loss of fertility by a bull can cause substantial loss to a potential calf crop. Each cow produces one calf per year; however, bulls should contribute to the calf crop by 25 to 60 times via siring 25 to 60 calves. Additionally, bulls influence their daughters’ production in the cow herd. Therefore, bull selection can be the most powerful method of genetic improvement in the herd, but bulls with low fertility, structural problems and low libido reduce the percent calf crop weaned